Watch | Thieves blow up Dutch museum door, steal prized golden helmet on loan from Romania

The video is grainy but ominous: Three hooded figures, clambering over one another to tug at a heavy access door of the Drents Museum — an art and history museum in Assen, Netherlands — and then an explosion and a flurry of sparks in the wee hours Saturday.

By daybreak, it had become clear that this was no amateur burglary. Dutch police said the explosion was part of an elaborate effort to break into the acclaimed museum and steal some of its treasures, including a prized helmet made of gold on loan from Romania.

“This is a dark day for the Drents Museum in Assen and the National History Museum of Romania in Bucharest,” Harry Tupan, director of the Drents Museum, said in a statement. “We are intensely shocked by the events last night at the museum. In its 170-year existence, there has never been such a major incident.”

Among the stolen artifacts were three golden bracelets and the golden helmet of Cotofenesti, an elaborately decorated, solid-gold headpiece from the fifth century BC. The helmet, which weighs a little over 2 pounds, features large studs across the top of the head.

It dates back to the ancient Dacians, who inhabited parts of the Balkan region. The helmet, which is well known in Romania and is believed to have been used in ceremonies, depicts various scenes, including someone sacrificing a lamb.

The helmet and several other golden artifacts were being displayed as part of a traveling exhibition from the National History Museum of Romania, and had been on display at the Drents Museum since July 2024.

While authorities declined to attach a monetary figure to the stolen goods, Romanian officials have called their value “incalculable” to Romania’s culture.

Neither representatives from the National History Museum nor officials from the Romanian Ministry of Culture could immediately be reached Sunday.

Dutch police say they are investigating a connection between the break-in and a nearby car fire. The thieves, they said, most likely set one car alight before escaping in another.

A similar art theft happened in November at MPV Gallery in Amsterdam, when thieves used a bomb to gain entry to an art gallery and stole two prints by American artist Andy Warhol.